Chapter {5} - WSDL

Abstract

This chapter describes the function of Web Services Description Language (WSDL) for a Web-service-based architecture. WSDL provides one form of Web service description, the functional description. The functional description of Web services falls into two broad areas: the abstract service definition, containing the service interface definition, and the service implementation description, containing the protocol binding and deployment information. The WSDL specification addresses the service description layer but not service composition and collaboration (both are also forms of service description). WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). WSDL is extensible to allow description of endpoints and their messages regardless of what message formats or network protocols are used to communicate however, the only bindings described in this document describe how to use WSDL in conjunction with SOAP 1.1, HTTP GET/POST, and MIME.